Feed dog awl assembly

ABSTRACT

A feed dog awl assembly for making pilot holes for a sewing machine needle includes a foot subassembly having means operable to drive the sewing foot in a vertically oscillating motion and an awl subassembly disposed above the bobbin of the sewing machine. The foot subassembly may include a selectively controllable operating lever operable to control the lowermost travel of the sewing foot.

United States Patent Blanc 1 1 Dec. 18, 1973 1 FEED DOG AWL ASSEMBLY 3,211,115 10/1965 13111111011 et a1. 112/2 [76] Inventor: Ferdinand H. Jean Blanc, 2719 N 1,397,071 11/1921 Becker 112/216 X 36th, Boise, Idaho 83703 FOREIGN PATENTS OR APPLICATIONS Filed J y 20 1972 258,272 5/1949 Switzerland 112/216 [21] Appl. No.: 273,569 Primary Examiner-Werner H. Schroeder Attorney-John W. Kraft [52] US. Cl 112/2, 112/48, 1l1l22//221369, ABSTRACT 151 1111. C1 D05b 27/02 A feed dog awl assembly for making Pilot holes for a [58] Field of Search 112/2, 7, 9, 21, Sewing machine needle includes a foot Subassembly 112/2 4 60 12127 130 2 237 having means operable to drive the sewing foot in a vertically oscillating motion and an awl subassembly 5 References Cited disposed above the bobbin of the sewing machine. The

UNITED STATES PATENTS foot subassembly may include a selectively controlla- 998 8 5 /19 H 12/239 ble operating lever operable to control the lowermost eggle 1.241,?33 10 1917 Herr 112 239 travel Ofthe Sewmg foot 891,210 6/1908 Cummings 112/239 2 Claims, 3 Drawing Figures PATENTEDDEB18 ma SHEET 10? 3 FIG.

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FEED DOG AWL ASSEMBLY FIELD OF INVENTION The present invention relates to sewing machine work manipulating apparatus, and more particularly to sewing machine work manipulating apparatus including feed dog awl means.

DESCRIPTION OF THE PRIOR ART Needle sewing machines commonly use and employ a mechanically actuated needle, carrying a thread, operable to penetrate material. In sewing heavy material, such as leather and canvas, the needle becomes dulled by the resultant stress of penetration. This necessitates frequent changes of needles, which in commercial applications may be difficult and costly.

Accordingly, it is an object of the present invention to provide means operable to penetrate material to permit a sewing machine needle to pass through fabric or other material more easily.

It is a further object of this invention to provide such hole making means and to control materials of varying thicknesses.

These and other objects shall become apparent from the description following, it being understood that modifications may be made without affecting the teachings of the invention here set out.

SUMMARY OF THE INVENTION Generally, a feed dog awl assembly for making pilot holes for a sewing machine needle includes a foot subassembly having means operable to drive the sewing foot in a vertically oscillating motion and an awl subassembly disposed above the bobbin of the sewing machine. The foot subassembly may include a selectively controllable operating lever operable to control the lowermost travel of the sewing foot.

A more thorough and comprehensive understanding may be had from the detailed description of the preferred embodiment when read in connection with the drawings forming a part of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of the feed dog awl assembly of this invention with a sewing machine housing drawn in broken lines for illustrative purposes.

FIG. 2 is a right front perspective view of the apparatus of the FIG. 1 including a portion of the machine housing broken away for illustrative purposes.

FIG. 3 is a left front perspective view, drawn to a larger scale, of the feed dog subassembly and a portion of the sewing foot.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings and more particularly to the FIGS. 1 and 2, the feed dog awl assembly of this invention is shown to advantage and generally identified by the numeral 10. The feed dog awl assembly is intended to be disposed in the structure of a commonly known needle-type sewing machine 1 1. The feed dog awl assembly 10 comprises a foot subassembly 12 and a feed dog subassembly 13.

The foot subassembly 12 is generally carried in a head housing 14 located at one of the terminal ends of an overhanging housing arm 15 of the machine 1 1. The arm 15 is provided with a rectilinearly disposed main shaft 16 which is driven by a suitable source (not shown). An eccentric-type cam 17 is mounted to the end portion of the main shaft 16 within the head housing 14. The cam 17 is operable to drive a commonly known, vertically disposed, needle bar 18 in a substantially vertically oscillating motion by means of a linkage rod 18 pivotally mounted to the face of the cam 17 and the needle bar 18 by suitable means.

The foot subassembly 12 includes a lifting lever subassembly 19 and a foot bar 20. The lifting lever subassembly 10 comprises a substantially vertically disposed cam follower 21 and a substantially horizontally disposed bar 22. The cam follower 21 is operable to frictionlessly ride about cylindrical camming walls 17 provided to one side of the sidewalls of cam 17. The camming walls 17' are operable to predeterminately, periodically actuate the cam follower 21 upwardly as the cam 17 rotates on the main shaft 16. The lifting lever bar 22 is slidably engageable distally from one of its terminal ends with a suitable slot 21 which is substantially vertically disposed in the uppermost terminal end of the cam follower 21. The terminal end of the lifting bar 22 opposite the slot 21' is fastened by means of a compressive clamp 23 to a point distally from the uppermost terminal end of the foot bar 20 which projects from the uppermost exterior side of the head housing 14. The foot bar 20 is a vertically disposed, substantially cylindrical rod operable to ride in and be guided by suitable holes in brackets 24 and 24 at the upper and lower portions of the head housing 14, respectively, as shown more clearly in the FIG. 2. The foot bar 20 projects from the upper and lower portions of the head housing 14. The foot bar 20 includes means operable to urge the bar 20 downwardly with respect to the head housing 14 and thus to simultaneously urge the lifting lever 19 and its follower 21 against the cam 17.

As shown in the FIG. 2, the urging means may include an urging spring 25 disposed contiguous with the lowermost terminal side of the upper housing bracket 24 and fastened to the foot bar 20 by means, such as weld 26.

The lowermost terminal end of the foot bar 20 is provided with a presser foot 28. The presser foot 28 may be provided with a cylindrical foot shank 29 and material-contacting forks 30. The foot shank 29 includes a substantially cylindrical upper portion 29' operable to slidably engage the lowermost terminal portions of the bar 20, and a tapered lower positioning portion 29" which is angled forwardly with respect to the machine 11 to suitably position the forks 30. The shaft 29 may be secured to the bar 20 by means of a locking screw 32 threadably engageable with a hole on the rearward side of the shank 29 to contact the foot bar 20. The forks 30 are bifurcated to provide a void in the path of the sewing machine needle 31 of the machine 1 1. The forks 30 are formed by a horizontally disposed, bifurcated plate which is fastened to the lowermost terminal end of the lower shank portion 29", and which includes a groove 30' disposed transversely with respect to the machine 11 from the forwardmost terminal end of the forks 30. It is to be understood that the forward end portions of the foot 28 are substantially longer than conventional presser foot plates, and flare outwardly with respect to the groove 30' between the forks 30 to facilitate material handling against the awl subassembly 13, as shown in the FIG. 3.

Referring now to the FIG. 2, the foot 28 and the foot bar 20 may be selectively controlled according to height to accommodate varying thicknesses of material by means of a presser foot operating lever 33. The lever 33 includes upstanding disk-like cam means 34 pivotally mounted to the head housing 14 distally adjacent the bar 20, and a rearwardly projecting lever rod 35 fastened to the cam 34. The foot bar 20 is provided with a suitable cam bracket portion 36 above the cam 34. In operation the operating lever 33 may be selectively rotated to cam the foot bar 20 to a desired level with lowermost travel of the bar 20, in a manner hereinafter described. An urging spring 25 is provided around the bar 20 between the interior side of the uppermost portion of the housing 14 and the uppermost terminal side of the bracket 24'. It is to be understood that the urging spring 25 is operable to urge the bar 20 downwardly to contact the cam 34.

Referring now to the FIGS. 1 and 3, the feed dog subassembly 13 is disposed beneath the presser foot 28 in a suitable housing 37 of the machine 11. The feed dog subassembly 13 includes a feed dog awl bracket 38. The bracket 38 includes a substantially inverted L- shaped plate 38' and a block portion 38 disposed on the uppermost terminal side of the horizontal leg of the plate 38'. The vertical leg on the lowermost terminal side of the horizontal leg of the bracket plate 38 is provided with a mounting hole 39 which is operable to engage mounting means 39 of the bobbin 40 of the machine 11. The uppermost terminal side of the block 38" includes an awl 41 and a needle hole 42. The awl 41 is an upwardly projecting cutting means operable to penetrate material, in a manner hereinafter later described. The needle hole 42 is disposed rearwardly with respect to the machine 11 and the awl 41, directly beneath the needle bor 18. The needle hole 42 provides a passage means for the sewing needle 31 carried on the bar 18 to pass through the subassembly 13 to permit thread carried by the needle 31 to engage the bobbin 40, commonly employed in sewing machines. It is to be understood that the subassembly 13 may be configured to provide a feed dog work table means by itself, or the block 38 may be disposed beneath commonly known feed dog material actuating means (not shown) which have been provided with means operable to permit the awl 41 to suitably project into the work area.

As shown in the FIG. 1, this invention may include a wax pot and stripper 43. The stripper 43 may be mounted to the uppermost terminal side of the machine arm distally from the head housing 14. The stripper 43 is operable to coat the thread 44.

In operation material is disposed between the foot subassembly 12 and the lowermost terminal side of the presser foot 28 and the outermost terminal side of the feed dog assembly 13. The cam 17 on the main shaft 16 drives the needle bar 18 and the foot bar in a predetermined vertically oscillating motion at a predetermined minimum height stopped by the operating lever 33. it is to be understood that the upward force is provided by the cam 17 and the downward force by the urging spring 25. The downward force of the foot assembly 12 is operable to press material between the lowermost terminal side of the presser foot 28 and the uppermost terminal side of the block 38, resulting in penetration of the awl 41 through the material. It is to be understood that the effective distance between the awl 41 and needle 31 and corresponding to the needle hole 42 is substantially separated by one stitch. Accordingly, it has been found to advantage to employ a blade-like awl 41 operable to cut an elongated hole to reduce the tolerance for alignment of the needle 31 with the hole punched by the awl 41.

Having thus described in detail a preferred apparatus which embodies the concepts and principles of the invention and which accomplishes the various objects, purposes and aims thereof, it is to be appreciated and will be apparent to those skilled in the art that many physical changes could be made in the apparatus without altering the inventive concepts and principles embodied therein. Hence, it is intended that the scope of the invention be limited only to the extent indicated in the appended claims.

I claim: 7

1. A feed dog awl assembly for a needle sewing machine including a head housing carrying and enclosing a rotating main shaft, a needle bar, and a feed dog housing under said housing over which work passes, comprising a foot subassembly including an upstandingly disposed disk-like cam having eccentric circumferential walls, said cam being mounted in said head housing on the terminal end of said suitably driven main shaft of said machine, said cam having a suitable linkage rod pivotally mounted to the flat face at the outer endward side opposite said shaft of said cam and to the needle bar of said machine to drive said needle bar with a vertically oscillating motion and a lifting lever subassembly having an upstandingly disposed follower means to follow camming portions on the cylindrical walls of said cam and having a substantially horizontally disposed lever lifting bar suitably mounted to the upper portion of said follower means, and a vertically disposed foot bar sliding in and being guided by holes in brackets in said head housing of said machine, said foot bar being fastened distally from its upper exterior terminal portion disposed above the uppermost terminal side of said head housing to said horizontal lifting lever by means of a compressive clamp, said foot bar and said lifting lever urging both downwardly; and a presser foot disposed at the lowermost terminal end of said foot bar; and feed dog subassembly including a substantially inverted L-shaped awl bracket having an upstanding vertical leg and a horizontal leg and a block portion on the uppermost terminal side of the horizontal leg of said awl bracket, said vertical leg of said bracket being provided with a suitable mounting hole mounting said bracket to said feed dog housing of said sewing machine, the uppermost terminal side of said block portion having an upwardly projecting awl and having a needle hole suitably distally rearwardly of said awl to provide a passageway through which a needle of said sewing machine may pass said awl being juxtapositioned approximately one stitch length from said needle hole.

2. The apparatus of claim 1 including a presser foot operating lever operable to selectively control the height of the lowermost travel of said presser foot, and including an upstandingly disposed disk-like cam means pivotally mounted to said head housing distally adjacent said foot bar, a rearwardly projecting rod fastened to said cam and a cam following bracket portion provided on said foot bar above said operating lever cam. 

1. A feed dog awl assembly for a needle sewing machine including a head housing carrying and enclosing a rotating main shaft, a needle bar, and a feed dog housing under said housing over which work passes, comprising a foot subasseMbly including an upstandingly disposed disk-like cam having eccentric circumferential walls, said cam being mounted in said head housing on the terminal end of said suitably driven main shaft of said machine, said cam having a suitable linkage rod pivotally mounted to the flat face at the outer endward side opposite said shaft of said cam and to the needle bar of said machine to drive said needle bar with a vertically oscillating motion and a lifting lever subassembly having an upstandingly disposed follower means to follow camming portions on the cylindrical walls of said cam and having a substantially horizontally disposed lever lifting bar suitably mounted to the upper portion of said follower means, and a vertically disposed foot bar sliding in and being guided by holes in brackets in said head housing of said machine, said foot bar being fastened distally from its upper exterior terminal portion disposed above the uppermost terminal side of said head housing to said horizontal lifting lever by means of a compressive clamp, said foot bar and said lifting lever urging both downwardly; and a presser foot disposed at the lowermost terminal end of said foot bar; and a feed dog subassembly including a substantially inverted Lshaped awl bracket having an upstanding vertical leg and a horizontal leg and a block portion on the uppermost terminal side of the horizontal leg of said awl bracket, said vertical leg of said bracket being provided with a suitable mounting hole mounting said bracket to said feed dog housing of said sewing machine, the uppermost terminal side of said block portion having an upwardly projecting awl and having a needle hole suitably distally rearwardly of said awl to provide a passageway through which a needle of said sewing machine may pass said awl being juxtapositioned approximately one stitch length from said needle hole.
 2. The apparatus of claim 1 including a presser foot operating lever operable to selectively control the height of the lowermost travel of said presser foot, and including an upstandingly disposed disk-like cam means pivotally mounted to said head housing distally adjacent said foot bar, a rearwardly projecting rod fastened to said cam and a cam following bracket portion provided on said foot bar above said operating lever cam. 